hey guys i droped off my 98 gt about 2 weeks ago for some upgrades and i should be getting it back this week some time but i'm curious as to what you might think on how much hp my car will make. so i'm putting in a 2200stall converter,trans cooler, pi intake, pi heads(only ported the exhaust ports to help w/detenation) w/comp cams 270's and bee hive springs,42lb injectors & 90mm mam. what i currently have on the car is bbk 75mm throttle body,c&l plenum,powerdyne suppercharger w/11lb pulley, 373 gears, stock exhaust except flowmasters out back. so i would like to know what you think i should see for #'s
how much should i see??
- Thread starter rw98gt
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the compression will be bumped up to 10.6 and thats why i ported the exhaust on the heads it will help with that issue (or thats what mike dez told me from dez racing) he has a great reputation and i trust him. as far as what the #'s were before w/a 6lb pulley it only put down about 230hp to the wheels so i bumped it up with an 11lb pulley and it was much better but i never had it dynoed with the pulley change. the powerdyne supercharger is at best an entry level supercharger and 11lb pulley swap is way less hp than doing the same swap to a pro charger or paxton.
i have had the set up w/6lbs for 3 years and 11lbs for 2 years if it seems like 11lbs is to much with this swap i will go back to 6lbs but i was told that i should not have an issue with the 11lb pulley.
after all this it would be awsome to get close to the 400rwhp mark. thats what i'm shooting for.
i have had the set up w/6lbs for 3 years and 11lbs for 2 years if it seems like 11lbs is to much with this swap i will go back to 6lbs but i was told that i should not have an issue with the 11lb pulley.
after all this it would be awsome to get close to the 400rwhp mark. thats what i'm shooting for.
10.6:1 and 11# of boost on a stock 2V bottom end is not going to give you much longevity. The HP numbers you'll see alone (425-450) are not really advisable on stock 2V shortblocks for extended periods, but couple the increase in compression that naturally occurs with the PI heads and Non-PI shortblock with forced induction, and I would be a little worried about the health of my factory reciprocating assembly.
Dez is a reputable tuner, but I know that the factory shortblocks are not made for those boost levels/compression ratios.
As for porting the exhaust valves to help with detonation, I am not sure that will be as effective as you think. Detonation occurs, because in nomral operation, the cylinder actually gets "preloaded" with fuel/air prior to spark delivery. The increase in compression (both through PI swap and forced induction) will make the motor MUCH more likely to detonate and I fear the exhaust porting won't help.
If I am correct, detonation actually occurs before the cylinder receives any spark due to the increase in compression inside the cylinder (thus igniting the preloaded air/fuel early), so the size of the exhaust valve might not help much since the exhaust valve won't actually be open when detonation is likely to occur.
Hope that helps.
Porting the exhaust will not make your engine more detonation resistant. In fact, I would argue the opposite, that a more restrictive exhaust would reduce the tendency for detonation. Exhaust gases are inert, thus more residual exhaust gasses left in the cylinder can reduce temperatures and the tendency for detonation. This is the theory behind the EGR operation: the strategy is to add the inert exhaust gasses at part throttle and you can reduce NOx, increase timing and make a little better gas mileage.
Your boost level is doable, but the tune will have to be spot on always. That makes it a less than reliable combination (ie, time bomb waiting for something to happen). The power numbers for this combination will come down completely to the tune, and if your mechanic/tuner is smart, they will pull out a LOT of timing. That will save the engine, but of course it'll make less power than it should and the exhaust gas temps will be way up, which can be bad for your engine in other ways.
E85 would be perfect for that combination, but pretty scary on pump gas. E85 is fun stuff... I am running 20psi on 10:1 compression and didn't find the limit yet.
Your boost level is doable, but the tune will have to be spot on always. That makes it a less than reliable combination (ie, time bomb waiting for something to happen). The power numbers for this combination will come down completely to the tune, and if your mechanic/tuner is smart, they will pull out a LOT of timing. That will save the engine, but of course it'll make less power than it should and the exhaust gas temps will be way up, which can be bad for your engine in other ways.
E85 would be perfect for that combination, but pretty scary on pump gas. E85 is fun stuff... I am running 20psi on 10:1 compression and didn't find the limit yet.
E85 would be perfect for that combination, but pretty scary on pump gas. E85 is fun stuff... I am running 20psi on 10:1 compression and didn't find the limit yet.
This statement is absolutely full of win!
+1
yea, my compression will be exactly 10.6.1 due to the pi heads and non pi bottom end. the pistons are different size on the non pi (larger"i think") squeezing more compression than the stock pi motor. however i'm not sure what the compression will be with the blower.
well i'm going to find out very soon the motor was put back in the car today and i should have my results soon enough. i'm realy hopeing to just get to 400hp i realy don't waunt over that due to the bottom end.
hey just in case something bad happends what would be a good short block that i could check out?
Skidzz
Tinkerbell
Modular Mustang Racing The "Street Mod 600" or "900," depending on what you want. Might as well start saving now, because I give your soon-to-be engine setup about a year...
